This study evaluated the benefit of Functional Endoscopic Sinus Surgery (FESS) in relieving symptoms of chronic rhinosinusitis in patients with minimal preoperative disease involvement as evident on C.T scan and assesses the accuracy of C.T in predicting the outcome of FESS using the Lund-Mackay staging system. 78 patients were stratified according to the extent of their pre-operative C.T disease involvement. Pre and Post operative symptom status were evaluated using Visual Analogue Score (V.A.S) Questionnaire. Using a chi-square test, no statistically significant difference in outcome following FESS was found between those with minimal changes and those patients with more extensive involvement on C.T. Patients benefited from surgery irrespective of pre-operative C.T score. We conclude from this study that FESS appears to have a beneficial role in relieving symptoms of chronic rhinosinusitis in patients with minimal as well as more extensive preoperative C.T disease involvement.